1. Field of the Invention
The present invention relates generally to the field of photography. More specifically, the present invention discloses a camera system for creating special effect images in the out-of-focus highlights of photographs.
2. Statement of the Problem
A wide variety of special effects have been used for many years in photographs and motion pictures. It is important for the photographer to be able to control, alter, or manipulate the photographic image for practical as well as artistic and aesthetic reasons. In particular, there is a need to incorporate special effects in a photographic image to attract the viewer's attention or interest. For example, advertisers want their logos to be seen and recognized in a subtle, artful, pleasing, and novel manner.
Prior Art--Photographic Filters
Photographic filters have long been used to create a variety of special effects. Filters are perhaps most commonly used to correct the color balance of the ambient light to that of the imaging medium. For example, when using daylight-balanced slide film, the photographer must use an 80 A blue filter when shooting indoors under 3200.degree. K tungsten lighting. In black-and-white photography, a red filter is often used to darken the sky and make clouds more pronounced. Graduated filters can also be used to darken a bright sky while leaving the lower portion of the image unchanged. Star filters are used to create a star burst or sun ray effect on the highlights of a photographic image. A piece of net or stocking in front of the lens can be employed to accomplish similar special effects in the highlights of a photograph. A net or stocking also tends to soften or blur the highlights. However, neither of these approaches creates coherent special effect images in the out-of-focus areas.
Several lenses and adapters allow a filter to be inserted between the objective lens and the camera. For example, the adapter used to attach a Nikon.TM. still camera lens to an Aaton.TM. 16 mm motion picture camera allows a color-correction or light attenuation gel to be placed over the rear aperture of the adapter. Some large telephoto lenses for Nikon.TM. and Canon.TM. cameras allow a filter to be screwed onto threads at the rear of the lens before the lens is mounted to the camera body. Other lenses include an intra-lens slot that accepts nets, gels, or glass filters. Some allow the filter to be dropped directly into the slot, while others must have the filter premounted on a filter-holding stage that can be inserted into the slot. Some video cameras include an internal disk with various color-correcting and/or light-attenuating filters that are rotated into place in front of the image plane via an external wheel, knob, or lever. A specific example of this is the Sony.TM. BVW400A Beta camera/recorder. However, none of these approaches are capable of creating coherent special effect images in the out-of-focus highlights of a photograph.
Prior Art--Masking and Matte Boxes
Matte boxes and masking techniques have long been used to fix the shape or outline of the whole picture (e.g., to create keyhole, binocular, or split screen effects). This can be accomplished by mounting a matte box or mask in front of or behind the camera lens. A number of prior art patents in this field include the following:
______________________________________ Inventor Patent No. Issue Date ______________________________________ Lanauze 2,504,255 Apr. 18, 1950 Mellert 2,641,952 June 16, 1953 Splendore 3,122,077 Feb. 25, 1964 Savage 3,918,078 Nov. 4, 1975 Williams et al. 5,233,375 Aug. 3, 1993 ______________________________________
Lanauze discloses a behind-the-lens filter and mask (column 3, lines 16-25). The mask serves as a means for controlling the outline or matting of the image recorded on film (e.g., a keyhole image).
The Mellert and Savage patents disclose other examples of devices for matting a photographic image (e.g., FIG. 9 and column 4, line 69, through column 5, line 9, of the Mellert patent).
Some cameras are equipped with a variable shutter feature that allows in-camera fades and dissolves. These special effects generally change the shape of the whole picture similar to a mask. In contrast, the present invention places a selected special effect image inside the out-of-focus highlights without changing the shape of the picture.
Prior Art--Inadvertent Lens Distortions
A number of prior art lenses with internal f-stop irises inadvertently change the size and shape of the out-of-focus highlights in a photograph. For example, the Zeiss.TM. 10-1 T2 Zoom lens creates pentagonal out-of-focus highlights that correspond to the shape of the pentagonal iris in this lens. Other lenses create hexagonal, octagonal, or nonagonal out-of-focus highlights. The iris changes the shape of the out-of-focus highlights, but cannot create coherent special effect images within the out-of-focus highlights. Additionally, the iris shape is a fixed characteristic of the lens design. The size of the aperture is a function of the f-stop chosen by the photographer in response to ambient light conditions in any given photographic situation.
Anamorphic lenses can also inadvertently create elliptical out-of-focus highlights in photographs. Here again, the size and shape of the elliptical highlights are fixed characteristics of the lens design. This approach cannot be used to create arbitrary, coherent special effect images.
3. Solution to the Problem
None of the prior art references uncovered in the search show a camera system for creating a selected coherent special effect image in the out-of-focus highlights of a photograph by interposing a transparent image cell between the objective lens and focal plane of a camera. The image cell is positioned along the optical axis of the camera to create the desired special effect image without otherwise affecting the photographic image.